Blasting machine



April 3, 1934. PEK' 1,953,566

7 BLASTING MACHINE Filed Jan. 24. 1934 2 Sheets-Sheet. 1

INVENTOR 6. uPi-k,

2 Sheets-Sheet 2 INVENTOR Patented Apr. 3, 1934- BLASTIN G MACHINE.Louis D. Peik, Warren, Ohio, assi gnor to The Wean Engineering Company,Inc., Warren, Ohio, a corporation of Ohio Application January 24,

17 Claims.

This invention relates to blasting machines of the centrifugal type andis adapted for the projecting of abradant particles such as sand, shotor othergrits. My machine is characterized by improved results andparticularly by its ability to deliver the abradant around a selectedportion only of the periphery. Generally speaking, centrifugal blastingmachines discharge with greater or less uniformity all the way aroundthe periphery, and since the normal way of handling material to betreated requires that it lie to one side only of the centrifugal wheel,it becomes necessary to shroud or shield the remaining portion of suchheads. This procedure is bad principally because the shroud is itselfrapidly worn away and the abradant is rapidly deteriorated. It is noexaggeration to state that in using centrifugal heads of ordinary typefrom half to three-quarters of the discharged abradant does not reachthe article to be blasted. My improved machine has directionalproperties; that is to say, it discharges abradant around a portion onlyof the periphery and the zone of discharge may be nicely controlledso'that it is possible to project the blast over a desired limited zone.

I providev a rotatable head having a central openingwith a passage orpassages extending from such opening to the periphery of the wheel,which passages are preferably spirals extending outwardly or rearwardlywith respect to the direction of rotation. Within the central opening Iplace a normally stationary container, which container has a passage ofperipheral length through which blast particles may be fed from thecontainer to the passage or passages in the head. I employ'an impellerwithin the container and feed blast particles to such impeller,

whei'eby uniform feeding of the blast particles to the rotatable head isobtained. Since the feeding of blast particles from the container to therotatable head takes place only over a limited range, the discharge iscorrespondingly limited. I make provision for adjusting the orientationof the container so that the orientation of the discharge zone may belikewise varied, and

" I also provide for adjusting the peripheral length of the openingthroughwhich the blast particles are supplied so that the annular lengthof the discharge zone may be likewise controlled.

I have found that'in order to get the best -results it is highlydesirable'to use passages .of generally spiral form in the head, whichpassages serve to feed the particles at rapidly increasing velocitytoward the periphery of the wheel. I there provide discharge or impactsurfaces against which the particles strike and from which they reboundto be discharged from the head. This arrangement gives a nicety ofcontrol which is 1934, Serial No. 708,118 (Cl. 51--9) ordinarily verydifficult if notimpossible to obtain and insures highly eflicientblasting.

In the accompanying drawings illustrating a. present preferredembodiment of the invention, Figure 1 is a section in the plane of thehead taken on the line I-I of Figure 2;

Figure 2 is a transverse section taken on the line II-II of Figure 1;

Figures 3, 4 and 5 are views showing various sizes of filler blockswhich may be employed for the purpose of adjustingthe peripheral lengthof the opening in the central feeding container; and

Figure 6 is a view corresponding to a portion of Figure 1 but showing amodification.

Referring first to Figures 1 and 2, the head comprises a wheel,indicated generally by the reference character 2, mounted on a shaft 3which is supported in bearings 4 and carries a grooved pulley 5 fordriving from a suitable'motor. The wheel 2 comprises a disc 6 having ahub 7, whereby it is mounted on the shaft 3, a ring 8 concentric withthe disc 6 and interposed segments 9 forming the discharge passages forthe abradant. The wheel is assembled by means of screws 10.

The wheel has a central cylindrical opening 11 and a stationary member12, held on a ring-like support 13, extends into this opening. Thesupport 13 is provided with slots14 to accommodate bolts 15 so that byloosening'the bolts the member 12 can be rotatablyadjusted, therebychanging its orientation. The innermost end of the member 12 has anopening 16 through which there projects an impeller 17 carried by thedisc 6. The impeller 17 is provided with radial blades 18 which serve tofeed abradant particles to the wheel. The abradant is supplied in thefirst instance through a tube 19and discharged through a central opening20' in the member 12 into an impeller chamber 21. This chamber has apcripheral surface 22 which is generally in the form of an involutespiral. The chamber has a peripheral outlet 23, one face of which isformed by an extension of the surface 22 and the other of which isformed by a filler block 24 held in place by screws 25. The peripherallength of the opening 23 may be varied" by using filler blocks of dif-.ferent sizes as indicated at 24a and 24b in Figures 1, 4 and 5. Thecentral container with its impeller blades 18 serves to discharge theabradant material at a uniform rate to the wheel, and I have found thatthe use of an involute'chamber;

a straight-bladed impeller, means for varying the orientation of thecontainer outlet, and means for varying the peripheral length of suchoutlet are all important if the best results are to be obtained. Thedirection of rotation of the head is indicated by an arrow R in Figure1, and it sage 23 is received by spiral passages 26 consti- 2 wardlywith respect'to such direction of rotation.

The abradant which is fed through the pasminate adjacent the peripheryof the wheel in radial extending passages 28'. The rearward faces of thepassages 28 (considering the direction of rotation) are providedwithimpact plates 29 having abrasion resistant impact surfaces 30.

Such surfaces may be an exceedingly hard material such astungsten-carbide or they maybe of some material. such as rubber. Theseimpact plates are slipped into position through openings 31 in the sidefaces of the wheel6 and the disc8 and are held in place by keys 32 whichare slightly tapered and are driven into place.

When abradant reaches the inner end of a passage 26 it is movedoutwardly as the wheel rotates at high velocity and the velocity of eacha particle is raised to an increasingly higher figure as it approachesthe periphery of the wheel. The

impact plate 29 lies in the path of the abradant and the abradantstrikesthe face of such plate and is'thrown off at high velocity. I haveindicated by an arrow P. the path of a particle through one of thepassages-26 and by. an arrow P- -1 the path of such particle after itstrikes the impact plate. It will be noted thatthe forward faces 33 ofthe radial passages 28' are ex-- tending forwardly and outwardly so asto provide clearance for the rebounding particles. The

radially extending openings 28 should beat least as wide as the passages26.

It will be noted frornFigure 1 that the outer surface of the centralcontainer is not truly cylindrical but is relieved for a distanceforwardly (considering the direction of. rotation of the wheel) of theopening 23. This is indicated at 34. I have found that the provision ofa space in this manner materially aids in the feeding of abradant to thewheel and prevents choking.

Figure 6 shows a modified construction wherein the impact surface,instead of being radial as in Figure, l, is in the form of a pocket 50.This pocket has a lining 51 of a suitable material such as rubber ortungsten carbide. The pocket is formed by providing a radially extendingsurface 52 and an overhung forwardly extending lip 53. It'is my beliefthat with this .form of impact surface some particles are trapped in thepocket as soon as the feeding of abradant through the head commences,and that while there is probably a more or less constant replacement ofthe trapped particles, there will remain at all times a sufilcientnumber of them in the pocket to reduce the amount of wear on the impactsurface.

My improved wheel discharges around a portion only of its periphery. Theorientation of the discharge zone may be readily controlled by adjustingthe-orientation of the discharge passage 23, and the size of the zonemay be readily controlled by adjusting the peripheral length of suchpassage. The edges of the zone are quite sharply defined so that surfaceblasting may be carried out accurately and successfully over such zoneand maximum efliciency obtained from the abradant. It is unnecessary toshroud the wheel by impact surfaces for receiving the major portion ofthe abradant as is the case with most devices of this character; andwhile, as a matter of plant cleanliness, the head will generally beshrouded, there is substantially no dischargeof particles outside thecontrolled zone.

The speed and character. of the surface blasting effect may be varied bychanging the speed of the wheel and by the size and character of theabradant employed. My improved head will operate successfully with anyof the known abradants in .particle form, such as sand, shot or steelgrit.

While I have illustrated and described preferred embodiments ofmyinvention, it will be understood that the same is not limited theretobut may be otherwise. embodied and practiced within thescope of thefollowing claims.

.I claim:

1. A blasting machine comprising a rotatable head having a spiralpassage therein extending outwardly and rearwardly with respect to thedirection of rotation of the head and terminating adjacent the peripheryof the head, means for supplying blast particles to the passage at apoint remote from the periphery of the head,

the head having a discharge surface adjacent the end of the spiralpassage inclined to the direction of travel of particles through thepassage and adapted to make contact with the particles supplied throughthe passage to change the direction thereof and effect discharge of thesame from the head.

2. A blasting machine comprising a rotatable head having a spiralpassage therein extending outwardlyand rearwardly with respect to thedirection of rotation of the head and terminating adjacent the peripheryof the head, means for supplying blast particles to the passage at apoint remote from the periphery of the head, the head having adischargesurface adjacent the end of the spiral passage inclined to the directionof travel of particles through the passage and adapted to make contactwith the particles supplied. through the passage to change the di-'rection thereof and effect discharge of the same from the head, thespiral passage being of such limited length that the last-mentionedsurface lies 'in the normal path of substantially all the particles fedthrough the passage.

3. A blasting machine comprising a rotatable head having a spiralpassage therein extending outwardly and rearwardly with respect to thedirectionof rotation of the head and terminating adjacent the peripheryof the head, means for supplying blast particles to the passage at apoint remote from the periphery of the head, the head having a radiallyextending discharge surface adjacent the end of the spiral passageinclined to the direction of travel of particles through the passage andadapted tomake contact with the particles supplied through the passageto change the direction thereof and effect discharge of the same fromthe head.

4. A blasting. machine comprising a rotatable head having a spiralpassage therein extending outwardly and rearwardly with respect to thedirection of rotation of the head and terminating" I outwardly andrearwardly with respect to the direction of rotation of the head andterminating adjacent the periphery of the head, means for supplyingblast particles to the passage at a point remote from the periphery ofthe head and a discharge passage adjacent the periphery of the headmaking connection with the spiral passage and having an impact surfacein the nor'-- mal path of particles fed through the spiral passage.

- 6; A blasting machine comprising a rotatable head having a spiralpassage therein extending outwardly and rearwardly with respect to thedirection of rotation of the head and terminating adjacentthe peripheryof the head, means for supplying blast particles to the passage at apoint remote from the periphery of the head, and a discharge passageadjacent the periphery of the head making connection with the spiralpassage and having an impact surface in the normal path of particles fedthrough the spiral passage, the

I discharge passage flaringoutwardly.

' head, a normally stationary container within the spiral passage.

'1. A blasting machine comprising a rotatable head having a spiralpassage therein extending outwardly and rearwardly with respect to thedirection of rotation ofthe head and terminating ing from the centralopening to the periphery of the head, a normally stationary containerwithin the central opening, said container having a passage of limitedperipheral le g h through which blast particles may be fed from thecon-,

tainer to the passage, and means ior supplying blast particles to thecontainer.

9. A blasting machine comprising a rotatable head having a centralopening, a passage extending from the central-opening to the peripheryof the head; a normally stationary container within the central opening,said container havinga passage of limited peripheral length throughwhich blast particles may be fed from the container to the passage, andmeans for supplying blast particles to the container, the orientation oithe passage in the container being adjustable. :110. A blasting machinecomprising a rotatable head having a central op'ening, a passageextending from the central opening to the periphery of thehead, anormally stationary container within the central opening, said containerhaving a passage of limited peripheral length through which blastparticles may be fed from the con; tainer to the passage;-and means forsupplying blast particles to thecontainer, the peripherallengthv of thepassage in the container being adjustable.

11. A blasting machine comprising a rotatable 1 head having ace'ntralopening, a passage extending from the opening to the peripheryof the central opening, said container having a passage or limitedperipheral length through which blast particles maybe fed from thecontainer to the passag'e in theheada flller block defining a portion 01the passagein the container, and means for supplying blast particles tothe container.

- 12. A blasting'machine comprising a rotatable" head having'a centralopening, a passage extending from the central opening to the peripheryof the wheel, a normally stationary container within the centralopening, said container having a passage extending outwardly andforwardly with respect to the direction of rotation through which blastparticles may be fed from the container to the head, and means forsupplying blast particles to the container.

13. A blasting machine comprising a rotatable head having'a centralopening, a passage extending outwardly and rearwardly with respect tothe direction of rotation, a normally stationary container within thecentral opening, said container having a passage extending forwardly andoutwardly with respect to the direction of rotation of the head andthrough which passage blast particles may be fed from the containerplying blast particles to the container.

.14. A blasting machine comprising a rotatablehead having a centralopening, a passage extending from such" opening to the periphery of. thehead, a normally stationary container within the central opening, saidcontainer having an -to the passage in the head, and means for sup-'inner peripheral surface which is a forwardly andoutwardly extendingspiral with respect to the'direction of rotation of the head, thecontainer having a passage of limited peripheral length through whichblast particles may be fed fromthe container to the passage in the head,and means for supplying blast particles to the container.

15. A blasting machine comprising a rotatable head having a centralopening, a passage extending from such central opening to the peripheryof the head, a normallysta'tionary container within the central opening,said container having a passage of limited peripheral length throughwhich blast particles may be fed from the container to the passage inthe head, means for 'supplying blast particles to the container, and animpeller in thecontainer for feeding such particles through the passagein the container.

-16. A blasting machine comprisingza. rotatable tending from suchcentral opening to the periphery of the head, a normally stationarycontainer within the central opening, said container having a passage oflimited peripheral length through which blast particles may befed fromthe con-- tainer to the passage in the head, means for supplying blastparticleslto the'container, and an impeller in the container for feedingsuch particles through thepassage in the container, the impeller havingradial blades.

1'1. A blasting machine comprising arotatable head having a centralopening ofcircular cross section, a passage extending from such centralopening to'the periphery of-the head, anormally stationary containerwithin the central I opening, the container having a passage oi. limitedperiph eral length through which blast particles may be fed from thecontainer to the-passage in the head, the container beinggenerally'circular in .head" having a central opening, a passageexexternal cross section but having such sur'i'ace relieved iorwardly'of the container passage, and means for supplying blast piu'ticlesto-the container.

' LOUIS RPM.

